Apparatus and method for a mobile telecommunications system

ABSTRACT

An apparatus comprising circuitry configured to perform a transport channel processing chain, the transport channel processing chain comprising a sub-carrier puncturing function, the sub-carrier puncturing function comprising puncturing, in each subframe of a composite transmission time interval, a set of subcarriers from at least one mapped physical resource block.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.16/495,103, filed Sep. 18, 2019, which is based on PCT filingPCT/EP2018/057147, filed Mar. 21, 2018, which claims priority to EP17162920.7, filed Mar. 24, 2017, the entire contents of each areincorporated herein by reference.

TECHNICAL FIELD

The present disclosure generally pertains to entities and user equipmentof a mobile telecommunications system.

TECHNICAL BACKGROUND

The term “Internet of things” (IoT) denotes the inter-networking ofphysical devices, vehicles, buildings, and other items that are providedwith electronics, software, sensors, actuators, and network connectivitythat enable these objects to collect and exchange data. Such objects arealso referred to as “connected devices” and “smart devices”.

Machine-type Communication (MTC) enables IoT devices to exchangeinformation in an autonomous way without human intervention. 3GPP is inthe process of improving LTE networks for Machine-type Communication(MTC). Examples are enhanced NB-IoT (eNB-IoT) with new power classes,improved mobility support and multicast messaging, or furtherenhancements for eMTC (feMTC) including VoLTE support and multicastmessaging. These improvements are the next steps in the direction of 5Gnetworks for massive MTC (mMTC).

eMTC (enhanced Machine Type Communication) is a 3GPP IoT technology thatsupports low-cost and high coverage for such machine-type communicationdevices. The technology is based on Long Term Evolution (“LTE”) and eMTCdevices are supported within an LTE host carrier.

Long Term Evolution (“LTE”) is a candidate for providing therequirements of 5G, which is a wireless communication technologyallowing high-speed data communications for mobile phones and dataterminals and which is already used for 4G mobile telecommunicationssystems. Other candidates for meeting the 5G requirements are termed NewRadio Access Technology Systems (NR). An NR can be based on LTEtechnology, just as LTE was based on previous generations of mobilecommunications technology. LTE is based on the GSM/EDGE (“Global Systemfor Mobile Communications”/“Enhanced Data rates for GSM Evolution” alsocalled EGPRS) of the second generation (“2G”) and UMTS/HSPA (“UniversalMobile Telecommunications System”/“High Speed Packet Access”) of thethird generation “3G”) network technologies. LTE is standardized underthe control of 3GPP (“3rd Generation Partnership Project”). There existsa successor LTE-A (LTE Advanced) allowing higher data rates than thebasic LTE which is also standardized under the control of 3GPP. For thefuture, 3GPP plans to further develop LTE-A, such that it will be ableto fulfill the technical requirements of 5G.

Although there exist signaling techniques for Machine-type Communication(MTC), it is generally desirable to improve the signaling in suchtechnologies.

SUMMARY

According to a first aspect the disclosure provides an apparatusincluding circuitry configured to perform a transport channel processingchain, the transport channel processing chain including sub-carrierpuncturing function, the sub-carrier puncturing function includingpuncturing, in each subframe of a composite transmission time interval,a set of subcarriers from at least one mapped physical resource block.

According to a further aspect, the disclosure provides an apparatusincluding circuitry configured to receive sets of a predefined number ofsubcarriers in each subframe and consider the remaining subcarriers asbeing punctured.

According to a further aspect the disclosure provides a method forperforming a transport channel processing chain, the transport channelprocessing chain including sub-carrier puncturing, the sub-carrierpuncturing function including puncturing, in each subframe of acomposite transmission time interval, a set of subcarriers from at leastone mapped physical resource block.

Further aspects are set forth in the dependent claims, the followingdescription and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are explained by way of example with respect to theaccompanying drawings, in which:

FIG. 1 illustrates a PUSCH PRB with normal CP configuration;

FIG. 2 illustrates the PUSCH transport channel processing chain;

FIG. 3 illustrates the order of resource element mapping for PUSCH infeMTC;

FIG. 4 illustrates repetition coding for PUSCH;

FIG. 5 shows an example mapping of a transport block to 3 subcarriersover 4 subframes in NB-IoT;

FIG. 6 shows an example method of transmission of a 3 subcarrier sub-PRBtransmission;

FIG. 7 shows a PUSCH transport channel processing chain includingsubcarrier puncturing and rearrangement;

FIG. 8 illustrates a transmission of a 6 subcarrier sub-PRB according toan embodiment;

FIG. 9 shows a transmission of a 6 subcarrier sub-PRB according to anembodiment;

FIG. 10 shows the generation of low PAPR 3-subcarrier sub-PRBtransmission according to an embodiment.

FIG. 11 shows the transport and physical channel processing chain forthe generation of a low PAPR 3-subcarrier sub-PRB transmission; and

FIG. 12 shows an embodiment of a general purpose computer that canfunction as any type of apparatus or entity, base station or new radiobase station, transmission and reception point, or user equipment asdescribed herein.

DETAILED DESCRIPTION OF EMBODIMENTS

Before a detailed description of the embodiments under reference of FIG.1, general explanations are made.

In the LTE Uplink (LTE UL), the base station scheduler allocatesresources to User Equipments (UEs) to use for the transmission ofpackets in the UL. When data is to be transmitted by the UE, these ULresources are Physical Uplink Shared Channel resources (PUSCH).

As the path loss between the UE and the base station increases, the sizeof an Uplink allocation to a UE decreases, according to scheduler policyat the base station. It is advantageous to reduce the PUSCH allocationto the UE since the UE is transmit power limited (typically the maximumUE transmit power is 23 dBm). By narrowing the transmission bandwidth, atargeted power spectral density (PSD) of the signal received by the basestation can be maintained. It is advantageous to work with anapproximately constant PSD at the base station since (1) thedemodulation error rate performance of the PUSCH transmission is afunction of the PSD, (2) reception of PUSCH with similar PSDs at thebase station reduces the dynamic range of the base station receiver and(3) reception of PUSCH with equal PSDs mitigates against spectralleakage of a PUSCH received with high PSD from one PUSCH interferingwith reception of a PUSCH with low PSD in adjacent frequency resources.It is also advantageous to transmit with smaller amounts of physicalresource (at a higher PSD) since this allows for more PUSCH (and hencemore UEs) to be multiplexed into the available physical resources.

In Release-14 feMTC (and earlier releases), the minimum UL resource thatcan be allocated to a UE is 1 Physical Resource Block (PRB) made up of12 sub-carriers.

The embodiments described below disclose an apparatus includingcircuitry configured to perform a transport channel processing chain,the transport channel processing chain including sub-carrier puncturingincluding circuitry configured to perform a transport channel processingchain, the transport channel processing chain including sub-carrierpuncturing function, the sub-carrier puncturing function includingpuncturing, in each subframe of a composite transmission time interval,a set of subcarriers from at least one mapped physical resource block.

It will be understood that the term “transport channel processing chain”includes elements that are described in 3GPP specifications as a“physical channel processing chain” (where in the transmitter, transportchannel processing is performed before physical channel processing). Thegeneral term “transport channel processing chain” used herein thusincludes some aspects of transport channel processing and some aspectsof physical channel processing.

An apparatus as described in the embodiments may for example be a mobiletelecommunications system entity, in particular user equipment, a basestation (eNodeB), or the like. In particular, the apparatus includingcircuitry configured to perform a transport channel processing chain,the transport channel processing chain including sub-carrier puncturingmay be a User Equipment (UE) that transmits a PUSCH transmission to abase station.

Circuitry may include at least one of: processor, microprocessor,dedicated circuit, memory, storage, radio interface, wireless interface,network interface, or the like, e.g. typical electronic components whichare included in a base station, such as an eNodeB.

The apparatus may for example be used in an IoT-device for theinter-networking of connected devices and smart devices. For example,the apparatus may be used in physical devices, vehicles, buildings, andother items that are provided with electronics, software, sensors,actuators, and network connectivity that enable these objects to collectand exchange data.

In particular, the apparatus may be used in a Machine-type Communication(MTC) scenario to allow the exchange of information in an autonomous waywithout human intervention.

The apparatus may for example be a 3GPP compliant communication device,e.g. an LTE or advanced LTE type device. The apparatus may for exampleprovide the requirements of 5G or other New Radio Access TechnologySystems (NR).

The apparatus may also be compliant with eMTC (enhanced Machine TypeCommunication), feMTC (further enhanced Machine Type Communication), orefeMTC (even further enhanced Machine Type Communication). Inparticular, the embodiments described below may provide a transmissionscheme for efeMTC sub-PRB PUSCH transmissions. The transmission schemefor efeMTC sub-PRB PUSCH transmissions according to the embodiments maybe compatible with legacy hardware.

A transport channel processing chain may for example relate to an ULShared Channel (UL-SCH) and/or Physical Uplink Shared Channel (PUSCH) orany other kind of shared communication channel.

Puncturing may relate to any function that selects subcarriers of aphysical resource block (PRB) and disregards the remaining sub carriers.

The circuitry may further be configured to puncture, in each subframe(TTI) of a composite transmission time interval (CTTI), a set ofsubcarriers from a mapped physical resource block (PRB). A compositetransmission time interval (CTTI) may be any composition of multipletransmission time intervals (TTIs). In the following embodiments, a TTIof a CTTI is also denoted as a subframe of the CTTI. Each subframe ofthe CTTI may be regarded as a PUSCH transmission. A compositetransmission time interval (CTTI) may for example include two or four ormore subframes (TTI).

The circuitry may be configured to puncture the set of subcarriers sothat the sets of subcarriers that are punctured are different betweensubframes (TTI). For example, in a subcarrier puncturing process, in thefirst subframe of a CTTI, the lowest 3 subcarriers of 12 subcarriers arekept and the other 9 subcarriers are punctured. Accordingly, in thesecond subframe of the CTTI, the next 3 subcarriers are kept and theother 9 subcarriers are punctured, etc.

The transport channel processing chain may for example be based on acomposite transmission time interval (CTTI) that includes two or moresubframes (CII). A composite transmission time interval (CTTI) may forexample include two, four, or twelve subframes, where each subframe is a1 ms transmission time interval (TTI).

The transport channel processing may include mapping, in each subframe(TTI) of a composite transmission time interval (CTTI), a transportblock to an integer number of physical resource blocks (PRBs) in asingle subframe (TTI).

The mapping may for example include mapping transport blocks to a 12subcarrier physical resource block (PRB) (integer number of physicalresource blocks=1) and the subcarrier puncturing is performed on these12 subcarriers (such as described with regard to the embodiment of FIG.6 below). Alternatively, transport blocks may be mapped to two physicalresource block (PRB) with 24 subcarrier in total (integer number ofphysical resource blocks=2) and the subcarrier puncturing is performedon these 24 subcarriers (such as described with regard to the embodimentof FIG. 9 below).

The transport channel processing may further include rearranging, thesubcarriers that remain after puncturing, in the frequency domain tooccupy the same frequency resources. A sub-carrier rearrangementfunction may for example be configured such that the non-puncturedsub-carriers are rearranged to fit into the allocated PUSCH resources.For example, only three sub-carriers may be allocated to a userequipment (UE) and the sub-carrier rearrangement function may rearrangethe subcarriers so that they are located in these three sub-carriersthat are allocated to a user equipment (UE). The remaining subcarriersmay for example be allocated to other user entities or they may remainunused. The transport channel processing chain may thus allow for thetransmission of sub-PRB PUSCH. Using a low number of allocatedsub-carriers in sub-PRB PUSCH may allow for massive MTC (mMTC).

Sub-PRB transmissions may allow for more UEs to be multiplexed into thesame resource in the frequency domain. Sub-PRB transmissions may allowfor higher PSD transmissions by the UE, improving decoding performanceat the base station. Still further, sub-PRB transmissions may have alower peak to average power ratio, leading to lower power amplifierbackoffs and higher power amplifier efficiency.

The embodiments described below may in particular provide a 3 subcarriersub-PRB transmission. The sub-PRB transmission may be encoded bypreviously known means.

The embodiments described below enable efeMTC to also support sub-PRBtransmissions. According to some embodiments, sub-PRB transmissions areimplemented such that they are compatible with legacy hardware.

The circuitry may be for example be configured to transmit a 3subcarrier sub-PRB transmission or a 6 subcarrier sub-PRB transmission.

The composite transmission time interval (CTTI) may include a fixedpredefined number of subframes and the base number of physical resourceblocks (PRBs) may be changed depending on the number of sub-carriers tobe used in a sub-PRB transmission. The fixed predefined number ofsubframes may for example be four subframes (e.g. CTTI=4 ms) and thebase number of physical resource blocks may either be one or two,depending on the number of sub-carriers used in a sub-PRB transmission.For example, for a 6 subcarrier sub-PRB transmission, the base number ofphysical resource blocks may be chosen as two (such as described withregard to the embodiment of FIG. 9 below), and for a 3 subcarriersub-PRB transmission, the base number of physical resource blocks may bechosen as one (such as described with regard to the embodiment of FIG. 6below).

Alternatively or in addition, the base number of physical resourceblocks (PRBs) may be fixed to a predefined number and the compositetransmission time interval (CTTI) may be adapted to the number ofsub-carriers used in the sub-PRB transmission. For example, the basenumber of physical resource blocks (PRBs) may be fixed to the predefinednumber 1 and the composite transmission time interval (CTTI) may changedepending on the number of sub-carriers used in the sub-PRBtransmission. For example, with a 3 sub-carrier transmission a CTTI=4 msmay be used (such as described with regard to the embodiment of FIG. 6below), whereas for a 6 sub-carrier transmission, a CTTI=2 ms may beused (such as described with regard to the embodiment of FIG. 8 below).

The circuitry may be configured to signal the sub-PRB allocation usingDCI (downlink control channel information) signaling. For example, thesub-PRB allocation to the device can be signaled using DCI (downlinkcontrol channel information) signaling, by extending the resourceallocation field in the DCI message that allocates UL resource (i.e. byextending the resource allocation field in DCI format 6-0A and/or DCIformat 6-0B). This can for example be implemented as a new DCI format(e.g. “DCI format 6-0C”).

The circuitry may also be configured to indicate its uplink transmissionpreferences to the network via higher layer signaling.

The transport channel processing chain may further include repeatingresource elements in other subcarriers of a sub-PRB waveform in the samesubframe (TTI). For example, a resource element of each OFDM symbol ofthe single carrier is repeated in other subcarriers of an N-subcarriersub-PRB waveform in the same OFDM symbol.

A sub-carrier repetition function may be added to emulate a singlesubcarrier transmission, i.e. a 3 sub-carriers PUSCH is emulated to havethe characteristics of a single sub-carrier PUSCH transmission which mayreduce the Peak-to-Average Power Ratio (PAPR).

The circuitry may for example be configured to map a transport block(TrBlk_n) to a single subcarrier per subframe, and the transport channelprocessing chain may include repeating the resource elements of eachsubframe of the single carrier in other subcarriers in the samesubframe. For example, a sub-carrier repetition function may beintroduced where a single sub-carrier is copied across X number ofconsecutive sub-carriers (e.g. X=3, 6, 9) of a sub-PRB waveform.

The circuitry may be configured to transmit the individual subcarrierswith different power. For example, a central subcarrier transmits 50% ofthe total transmit power and the two adjacent subcarriers each transmit25% of the total transmit power.

The transport channel processing chain includes multiplexing ofreference signals.

The circuitry may be configured to assign a user equipment (UE) toperform low Peak-to-Average Power Ratio (PAPR) uplink transmission viadownlink control message signalling.

Hence the embodiments may allow to create a transmission scheme forefeMTC sub-PRB PUSCH transmissions that reduces the peak to averagepower ratio of the transmitted waveform.

The embodiments described below also disclose an apparatus includingcircuitry configured to receive sets of a predefined number ofsubcarriers in each subframe and consider the remaining subcarriers asbeing punctured.

Such an apparatus may for example be a base station (eNodeB) that isconfigured to receive sub-PRB transmissions from User Equipment (UE).

The embodiments described below also disclose a method for performing atransport channel processing chain, the transport channel processingchain including sub-carrier puncturing. The transport channel processingchain may further include rearranging the subcarriers that remain afterpuncturing in the frequency domain to occupy the scheduled/allocatedfrequency resources. Still further, the transport channel processingchain may further include repeating resource elements in othersubcarriers of a sub-PRB waveform in the same subframe (TTI).

The embodiments also disclose a computer program including instructions,the instructions when executed on a processor performing a transportchannel processing chain, the transport channel processing chainincluding sub-carrier puncturing.

The embodiments also disclose a machine-readable medium storing such acomputer program.

FIG. 1 illustrates a PUSCH PRB with normal Cyclic Prefix (CP)configuration. A single PRB consists of 12 subcarriers and 14 SC-FDMAsymbols, where the 12 subcarriers are multiplexed and transmitted usinga DFT-s-OFDM waveform. The transmission time interval TTI (time intervalover which a transport block is transmitted) is 1 ms. Hence, when asingle PRB is assigned for PUSCH, the transport blocks are mapped toResource Elements (RE) occupying 12 subcarriers and 1 ms. Demodulationreference signals (DMRS) are inserted for channel estimation and forcoherent demodulation.

FIG. 2 illustrates the mapping operations of the PUSCH transport channelprocessing chain. At 201, CRC attachment is performed. 24 bit CRC isused. At 202, turbo coding is performed. A ⅓ code rate mother code isused. At 203, interleaving is performed. Bits are interleaved across atime span of at most 1 ms. At 204, rate matching is performed. In orderto create other code rates, repetition or puncturing of the output bitsmay be performed in a rate matching operation. At 205, scrambling isperformed. Scrambling may be UE specific, cell specific and slotspecific. At 206, modulation is performed. At the cell edge, QPSKmodulation is applied. 16 QAM can alternatively be applied, according toscheduler decisions. At 207, Resource element (RE) mapping is performed.The modulation symbols are mapped to subcarriers and SC-FDMA symbols inthe resource grid. At 208, reference signal (RS) generation isperformed. Demodulation reference signals (DMRS) are inserted into theresource element space to allow the base station to channel estimate andreceive the signal. At 209, DFT-s-OFDM signal generation is performed.The resource elements are applied to this function to create thetransmitted waveform.

FIG. 3 illustrates the order of resource element mapping for PUSCH infeMTC, i.e. how in feMTC modulation symbols are mapped to resourceelements in a frequency-first (dotted lines), time-second order (dashedlines).

The coverage of the PUSCH can be enhanced through repetition. In itsbasic form, when repetition coding is applied, for each TTI, thetransport channel processing chain is executed and an identical set ofphysical bits (and resource elements) is mapped in subsequent subframes. In a more sophisticated form, different redundancy versions(RVs) are mapped to different subframes (where different redundancyversions contain different sets of rate matched bits: different sets ofparity and systematic bits from the turbo code) when repetition isapplied. The redundancy versions can be cycled according to a knownpattern (e.g. RV 0,2,1,3), in which case “RV cycling” is said to beapplied. In either case, the transport channel processing chain isexecuted in each subframe and a set of bits is mapped to the PUSCH.

FIG. 4 illustrates repetition coding for PUSCH. The figure shows thesame transport block TrBlk_n being fed into the transport channelprocessing chain TrCH_proc and mapped to consecutive subframes. The basestation receiver can combine the received resource elements on asubframe by sub frame basis.

In NB-IoT [2], sub-PRB transmissions are possible. A sub-PRBtransmission consists of less than 12 subcarriers. Sub-PRB transmissionsof 1, 3 and 6 subcarriers are possible in NB-IoT. When a sub-PRBtransmission is used, the resources are expanded in the time domain:i.e. one transport block is mapped, interleaved and rate matched acrossmore than one subframe. The following combinations are applied: 1subcarrier and 8 subframes, 3 subcarriers and 4 subframes, 6 subcarriersand 2 subframes, or 12 subcarriers and 1 subframe.

FIG. 5 shows an example mapping of a transport block to 3 subcarriers/4sub frames in NB-IoT. This figure shows that by means of the transportchannel processing chain TrCH_proc a single transport block TrBlk_n isinterleaved, rate matched and mapped to resources consisting of 3subcarriers and 4 subframes. This form of mapping of transport blocks tophysical transmission resources shown in FIG. 5 is not compatible withlegacy feMTC hardware since it interleaves PUSCH transmissions acrossmultiple subframes, requiring buffering to be available in the UE andbase station that can be accessed and interleaved over multiplesubframes.

Sub-Carrier Puncturing

In the embodiments described below, sub-carrier puncturing is described.The sub-carrier puncturing is targeted at allowing for the transmissionof sub-PRB PUSCH.

In a first embodiment, the composite transmission time interval (CTTI)is variable and transport blocks are always initially mapped to a 12subcarrier PRB. A sub-PRB transmission is associated with a longer CTTIand in each subframe of the CTTI the following operations are performed:The transport block is mapped to an integer number of PRBs in a singlesubframe. In each subframe of the CTTI, a set of subcarriers ispunctured from the mapped PRBs. The set of subcarriers that arepunctured is different between subframes (e.g. the subcarriers that arepunctured are arranged according to a circular buffer principle). Andthe remaining subcarriers can be rearranged in the frequency domain tooccupy the same frequency resources and are modulated (e.g. viaDFT-s-OFDM) and transmitted.

FIG. 6 shows an example method of transmission of a 3 subcarrier sub-PRBtransmission. In each subframe of the CTTI, the transport block ismapped to 12 subcarriers, up to and including the resource elementmapping stage. Subcarrier puncturing is performed on these 12subcarriers. In the subcarrier puncturing process, in the first subframeof the CTTI, the lowest 3 subcarriers 601-10, 601-11, 601-12 of the 12subcarriers are kept and the other 9 subcarriers are punctured.Accordingly, in the second subframe of the CTTI, the next 3 subcarriers602-7, 602-8, 602-9 are kept and the other 9 subcarriers are punctured.Accordingly, in the third subframe of the CTTI, the next 3 subcarriers603-4, 603-5, 603-6 are kept and the other 9 subcarriers are punctured.Accordingly, in the fourth sub frame of the CTTI, the next 3 subcarriers604-1, 604-2, 604-3 are kept and the other 9 subcarriers are punctured.In a next operation, the remaining subcarriers are rearranged to occupythe same 3 subcarriers. Then, reference signals (RS) are generated andinserted into the 3 subcarriers of the sub-PRB transmission. Finally,the signal is DFT-s-OFDM modulated and transmitted.

The receiver (at the base station) may operate on similar principles. Itcan receive sets of 3 subcarriers in each subframe and consider theother 9 subcarriers as being punctured (e.g. by insertion of zero LLRs).This mixture of received symbols and punctured bits can be de-ratematched and combined in the receiver's soft combining buffer, as perlegacy operation.

According to this embodiment, the order of mapping of modulation symbolsto REs is now no longer in a frequency first, time second order (i.e. isnow different to the RE mapping order described in FIG. 3). In thisembodiment, the first 3 modulation symbols (indexed 0, 1, 2) are mappedto the first OFDM symbol of the first subframe, the next 3 modulationsymbols are mapped to the first OFDM symbol of the second subframe, etc.Still further, the modulation symbols indexed 12 to 14 are mapped to thesecond OFDM symbol of the first subframe, etc.

It will be understood that what is pertinent to the embodiments is theorder in which modulation symbols are finally mapped to resourceelements (i.e. the final mapping of modulation symbols to SC-FDMAsymbols and subcarriers). For clarity of exposition, this mapping orderis herein described in terms of subcarrier puncturing, subcarrierrearrangement, multiplexing and/or subcarrier repetition functions.However these functions can all be described and implemented in a singleresource element mapping function that produces the same mapping ofmodulation symbols to resource elements as described herein withreference to subcarrier puncturing, subcarrier rearrangement,multiplexing and/or subcarrier repetition functions.

FIG. 7 shows a PUSCH transport channel processing chain includingsubcarrier puncturing and rearrangement. Compared to FIG. 2, this figureincludes the additional steps of subcarrier puncturing 708 andsubcarrier rearrangement 709. Subcarrier puncturing 708 and subcarrierrearrangement 709 is performed e.g. as described above with regard tothe embodiment of FIG. 6.

It should be appreciated that although the sub-carrier puncturing wouldmean in each subframe the eNB would obtain only a fraction of therequired bits, the repetition does not need to be a multiple of theCTTIs. That is for example, if we use 3 sub-carriers and the CTTI is 4subframes, it is possible to have a repetition that is not multiples of4 subframes, e.g. the repetition can span 22 subframes. In contrast aTTI that is 4 ms, like in NB-IoT, would mean the repetition would occupya multiple of 4 sub frames.

FIG. 7 shows the operations of a UE. A base station may perform theinverse functions in the reverse order: first operation 711, then 709,708, . . . 702, and finally 701. In this inverse scenario, the PUSCHenters at 711.

FIG. 8 illustrates a transmission of a 6 subcarrier sub-PRB according toan embodiment. In each subframe of the CTTI, the transport block ismapped to 12 subcarriers, up to and including the resource elementmapping stage. Subcarrier puncturing is performed on these 12subcarriers. In the subcarrier puncturing process, in the first subframeof the C FI I, the lowest 6 subcarriers 801-7, 801-8, 801-9, 801-10,801-11, 801-12 of the 12 subcarriers are kept and the other 6subcarriers are punctured. Accordingly, in the second subframe of theCTTI, the next 6 subcarriers 802-1, 802-2, 802-3, 802-4, 802-5, 802-6are kept and the other 6 subcarriers are punctured. In a next operation,the remaining subcarriers are rearranged to occupy the same 6subcarriers. Then, reference signals (RS) are generated and insertedinto the 6 subcarriers of the sub-PRB transmission. Finally, the signalis DFT-s-OFDM modulated and transmitted.

The above method of creating sub-PRB transmissions is difficult to applyto 9 subcarrier transmissions. Hence in another embodiment the CTTI isfixed and transport blocks are initially mapped to a multiple of12-subcarrier-PRBs. Hence in this embodiment the CTTI is fixed at 4 ms(4 subframes) for 3, 6 & 9 subcarrier sub-PRB transmissions. For 3subcarriers it is rate matched to 12 subcarriers and 9 subcarriers arepunctured (75% of the subcarriers). For 6 subcarriers it is rate matchedto 2 PRBs (24 subcarriers) and 18 subcarriers are punctured (75% of thesubcarriers). And for 9 subcarriers it is rate matched to 3 PRBs (36subcarriers) and 27 subcarriers are punctured (75% of the sub carriers).

The transmission of a 3-subcarrier sub-PRB PUSCH is as shown in FIG. 6.

FIG. 9 shows a transmission of a 6-subcarrier sub-PRB according to anembodiment of a 6-subcarrier sub-PRB and a CHI of 4 ms. In each subframeof the CTTI, the transport block is mapped to 24 subcarriers (theprinciples of the mapping between sub-PRB size and number of subcarriersmapped to in transport channel processing is as explained with regardto), up to and including the resource element mapping stage. In thesubcarrier puncturing process, in the first subframe of the CTTI, thelowest 6 subcarriers 901-19, 901-20, 901-21, 901-22, 901-23, 901-24 ofthe 24 subcarriers are kept and the other 18 subcarriers are punctured.In the second subframe of the CTTI, the next 6 subcarriers 902-13,902-14, 902-15, 902-16, 902-17, 902-18 are kept and the other 18subcarriers are punctured. In the third subframe of the CTTI, the next 6subcarriers 903-7, 903-8, 903-9, 903-10, 903-11, 903-12 are kept and theother 18 subcarriers are punctured. In the fourth subframe of the CTTI,the next 6 subcarriers 904-1, 904-2, 904-3, 904-4, 904-5, 904-6 are keptand the other 18 subcarriers are punctured. The remaining subcarriersare rearranged to occupy the same 6 subcarriers. In all cases, thisre-arrangement can be achieved by the skilled person by choosing the setof modulation symbols to map into the REs that reflect the DFT-s-OFDMsub-carriers to be retained. Reference signals are generated andinserted into the 6 subcarriers of the sub-PRB transmission. The signalis DFT-s-OFDM modulated and transmitted.

As described before, NB-IoT uses sub-PRB PUSCH where the TTI of thePUSCH is extended to provide the number of physical resources (REs)equivalent to that of a PRB. In contrast the embodiment described abovedoes not extend the TTI but rather introduces a sub-carrier puncturingfunction. Since the TTI in the embodiments is not increased, therepetition does not need to span multiples of CTTI but rather multiplesof TTI.

As a consequence, the sub-carrier puncturing according to theembodiments described above may easier be implemented on legacy hardwarethan sub-PRB PUSCH of NB-IoT.

Sub-PRB Resource Allocation Signalling

As it has been described above, the transport channel processing chainmaps to an N subcarrier sub-PRB waveform. The sub-PRB allocation to thedevice can be signaled using DCI (downlink control channel information)signaling, by extending the resource allocation field in the DCI messagethat allocates UL resource (i.e. by extending the resource allocationfield in DCI format 6-0A and/or DCI format 6-0B). This can beimplemented as a new DCI format (e.g. “DCI format 6-0C”).

The current DCI format 6-0B as defined in [3] has a resource allocationfield that indicates a narrowband to the UE and the resources (i.e. PRBallocation) within the narrowband, as below:

$\left\lceil {\log_{2}\left\lfloor \frac{N_{RB}^{UL}}{6} \right\rfloor} \right\rceil$

MSB bits provide the narrowband index as defined in section 5.2.4 of [2]

In addition, 3 bits provide the resource allocation within the indicatednarrowband as specified in section 8.1.3 of [3].

The resource allocation information for uplink resource allocation type2 indicates to a scheduled UE a set of contiguously allocated resourceblocks within a narrowband as given in Table 8.1.3-1 of [4]. Accordingto this current scheme, a value ‘000’ of the resource allocation fieldallocates resource block 0, a value ‘001’ of the resource allocationfield allocates resource block 1, a value ‘010’ of the resourceallocation field allocates resource block 2, a value ‘011’ of theresource allocation field allocates resource block 3, a value ‘100’ ofthe resource allocation field allocates resource block 4, a value ‘101’of the resource allocation field allocates resource block 5, a value‘110’ of the resource allocation field allocates resource blocks 0 and1, and a value ‘111’ of the resource allocation field allocates resourceblocks 2 and 3.

According to the embodiments, DCI format 6-0B is extended by having aresource allocation field that indicates a narrowband, a PRB within thenarrowband and a set of contiguous subcarriers within the narrowband.

For a 3-subcarrier sub-PRB allocation in the set of contiguoussubcarriers within the narrowband 2 bits can indicate one of 4 sets of3-subcarrier contiguous allocations (starting at subcarrier 0, 3, 6 or 9within the PRB).

For a 6-subcarrier sub-PRB allocation, the set of contiguous subcarrierswithin the narrowband can be indicated by 1 bit where one of 2 sets of6-subcarrier contiguous allocations (starting at subcarrier 0 or 6within the PRB) can be indicated, or by 2 bits where one of 3 sets of6-subcarrier contiguous allocations (starting at subcarrier 0, 3 or 6within the PRB) can be indicated.

For either a 3-subcarrier or 6 subcarrier sub-PRB allocation 1 bit canindicate the number of subcarriers within the allocation and 2 bits canindicate the starting location of the allocated subcarriers within theallocation.

Hence the following resource allocation signalling for indicating thesub-PRB allocation could be applied: A resource allocation bit stringindicates the number of subcarriers and the starting subcarrier withinPRB. According to an embodiment, the resource allocation bit string‘000’ indicates a number of 3 subcarriers and a starting subcarrier 0.The resource allocation bit string ‘001’ indicates a number of 3subcarriers and a starting subcarrier 3. The resource allocation bitstring ‘010’ indicates a number of 3 subcarriers and a startingsubcarrier 6. The resource allocation bit string ‘011’ indicates anumber of 3 subcarriers and a starting subcarrier 9. The resourceallocation bit string ‘100’ indicates a number of 6 subcarriers and astarting subcarrier 0. The resource allocation bit string ‘101’indicates a number of 6 subcarriers and a starting subcarrier 3. Theresource allocation bit string ‘110’ indicates a number of 6 subcarriersand a starting subcarrier 6, and the resource allocation bit string‘111’ may be reserved.

The UE can be signaled (e.g. via RRC signaling) whether it shouldoperate in a sub-PRB transmission mode or not (and hence whether itshould interpret DCI as allocating sub-PRB transmissions or shouldinterpret DCI as allocating legacy (Release-14 and earlier) whole-PRBtransmissions).

Creating Low PAPR Sub-PRB Waveforms

According to the embodiments described below, in order to create lowPAPR 3-subcarrier sub-PRB waveforms, the transport channel processingchain maps to a single subcarrier per subframe. The resource element ofeach OFDM symbol of the single carrier is then repeated in the other twosubcarriers of the 3-subcarrier sub-PRB waveform in the same OFDMsymbol. Here, a 3-subcarrier sub-PRB waveform is an example and it hasbeen defined as the minimum number of sub-carriers for sub-PRBtransmission in efeMTC [1].

Any method of mapping to a single subcarrier per subframe can be appliedin this embodiment (e.g. the NB-IoT method described previously withreference to FIG. 5). In the following, we describe this embodiment withreference to an encoding methodology that is compatible with thesub-carrier puncturing previously described.

FIG. 10 shows the generation of low PAPR 3-subcarrier sub-PRBtransmissions according to an embodiment. According to this embodiment,the CTTI is 12 subframes. In each subframe of the CTTI, the transportblock is mapped to 12 subcarriers, up to and including the resourceelement mapping stage. In the subcarrier puncturing process, in thefirst subframe of the CTTI, the lowest subcarrier 1001-12 of the 12subcarriers is kept and the other 11 subcarriers are punctured. In thesecond subframe of the CTTI, the next subcarrier 1002-11 is kept and theother 11 subcarriers are punctured. In the third subframe of the CTTI,the next subcarrier 1003-10 is kept and the other 11 subcarriers arepunctured. In the fourth subframe of the CTTI, the next subcarrier1004-9 is kept and the other 11 subcarriers are punctured. In the 5thsubframe of the CTTI, the next subcarrier 1005-8 is kept and the other11 subcarriers are punctured. In the 6th subframe of the CTTI, the nextsubcarrier 1006-7 is kept and the other 11 subcarriers are punctured. Inthe 7th subframe of the CTTI, the next subcarrier 1007-6 is kept and theother 11 subcarriers are punctured. In the 8th subframe of the CTTI, thenext subcarrier 1008-5 is kept and the other 11 subcarriers arepunctured. In the 9th subframe of the CTTI, the next subcarrier 1009-4is kept and the other 11 subcarriers are punctured. In the 10th subframeof the CTTI, the next subcarrier 1010-3 is kept and the other 11subcarriers are punctured. In the 11th subframe of the CTTI, the nextsubcarrier 1011-2 is kept and the other 11 subcarriers are punctured. Inthe 12th subframe of the CTTI, the next subcarrier 1012-1 is kept andthe other 11 subcarriers are punctured. As a next operation, theremaining subcarriers are rearranged to occupy the same 1 subcarrier. Asa next operation, this single subcarrier is then repeated to create 3subcarriers containing identical resource elements. As a next operation,reference signals RS are generated and inserted into the 3 subcarriersof the sub-PRB transmission. The insertion operation is a form ofmultiplexing, whereby the reference signals and PUSCH REs aremultiplexed together. The reference signals themselves can be formed asrepeated resource elements in the subcarrier domain (alternatively, RScan be inserted into the single subcarrier prior to the subcarrierrepetition stage, as shown in FIG. 11, where the RS are inserted via amultiplexing stage 1111, prior to being repeated in the subcarrierrepetition stage 1112). The signal is DFT-s-OFDM modulated andtransmitted.

In an embodiment, the power of the individual subcarriers can bedifferent (e.g. the central subcarrier (bracket “central” in FIG. 10)transmits 50% of the total transmit power and the two adjacentsubcarriers each transmit 25% of the total transmit power). Thisarrangement concentrates the UE transmit power in the subcarrier that isfurthest away from interference from other UEs (e.g. adjacent channelleakage from other UEs that are scheduled in adjacent subcarriers).

FIG. 11 shows the transport and physical channel processing chain forthe generation of low PAPR 3-subcarrier sub-PRB transmissions. At 1109,a single subcarrier transmission is created at the “subcarrierrearrangement” stage. At 1111, multiplexing of reference signals intothe single subcarrier is performed. At 1112, in a subcarrier repetitionstage, a 3 times repetition of the subcarrier is performed in order toenable a low PAPR signal to be created in the DFT-s-OFDM stage. Theremaining operations are identical to FIG. 7.

For this embodiment, relative to a 3-subcarrier sub-PRB transmission,where the 3-subcarriers all transmit different resource elements (FIG.6), there are several ways that the transport block can be adapted tothe smaller amount of physical resource. The CTTI may be increased by afactor of 3 (e.g. as shown in FIG. 10) and the transport block size isunaffected. Alternatively, the CTTI is maintained (e.g. 4 ms CTTI) andthe transport block size (TBS) is reduced (e.g. by a factor of 3). Stillalternatively, the CTTI and TBS are maintained, but the modulation andcoding scheme (MCS) applied uses a higher MCS (e.g. if an MCS of QPSKrate 1/12 were used in the aspect shown in FIG. 6, an MCS of QPSK rate ¼could be used in the embodiment shown in FIG. 10, since FIG. 10 contains3 times less physical resource than FIG. 6).

FIG. 10 shows how a low-PAPR waveform for a 3-subcarrier sub-PRBtransmission can be created. It will be readily apparent to a skilledartisan that this technique can also be applied to the creation of alow-PAPR waveform for a 6-subcarrier sub-PRB transmission (through6-fold repetition of the single subcarrier created at the “subcarrierrearrangement” stage of FIG. 10).

As it has been described, in this method of creating low PAPR sub-PRBwaveforms the transport channel processing chain maps to L subcarriersper subframe (e.g. L=1). The resource element is then repeated M times(e.g. M=3) in the other subcarriers to form an N subcarrier sub-PRBwaveform (N=L*M). This method where the uplink signal from UE has a lowPAPR property can be implemented as a distinct capability of the device.In order to support this operation a UE can indicate its capability tosupport this operation. Still further, a UE can indicate its uplinktransmission preferences (e.g. low PAPR or legacy method) to the networkvia higher layer signaling (e.g RRC). Still further, thenetwork/base-station can instruct the UE to perform such low PAPR uplinktransmission via downlink control message signalling (e.g. downlinkcontrol information (DCI)). For example the DCI can indicate L and/or Mto the UE. The UE can then derive the parameters L and M parameters fromthe N parameter, where the rules for this derivation are indicatedeither by standardisation or by RRC signalling.

In the above DCI signaling, the location (in the subcarrier resourcespace) of the sub-PRB resource allocation can be indicated as previouslydescribed in the section “Sub-PRB resource allocation signalling” andthe DCI signaling described above can be used in addition to thatsignaling previously described.

Implementation

In the following, an embodiment of a general purpose computer 130 isdescribed under reference of FIG. 12. The computer 130 can beimplemented such that it can basically function as any type of apparatusor entity, base station or new radio base station, transmission andreception point, or user equipment as described herein. The computer hascomponents 131 to 140, which can form a circuitry, such as any one ofthe circuitries of the entities, base stations, and user equipment, asdescribed herein.

Embodiments which use software, firmware, programs or the like forperforming the methods as described herein can be installed on computer130, which is then configured to be suitable for the concreteembodiment.

The computer 130 has a CPU 131 (Central Processing Unit), which canexecute various types of procedures and methods as described herein, forexample, in accordance with programs stored in a read-only memory (ROM)132, stored in a storage 137 and loaded into a random access memory(RAM) 133, stored on a medium 140, which can be inserted in a respectivedrive 139, etc.

The CPU 131, the ROM 132 and the RAM 133 are connected with a bus 141,which in turn is connected to an input/output interface 134. The numberof CPUs, memories and storages is only exemplary, and the skilled personwill appreciate that the computer 130 can be adapted and configuredaccordingly for meeting specific requirements which arise when itfunctions as a base station, and user equipment.

At the input/output interface 134, several components are connected: aninput 135, an output 136, the storage 137, a communication interface 138and the drive 139, into which a medium 140 (compact disc, digital videodisc, compact flash memory, or the like) can be inserted.

The input 135 can be a pointer device (mouse, graphic table, or thelike), a keyboard, a microphone, a camera, a touchscreen, etc.

The output 136 can have a display (liquid crystal display, cathode raytube display, light emittance diode display, etc.), loudspeakers, etc.

The storage 137 can have a hard disk, a solid state drive and the like.

The communication interface 138 can be adapted to communicate, forexample, via a local area network (LAN), wireless local area network(WLAN), mobile telecommunications system (GSM, UMTS, LTE, etc.),Bluetooth, infrared, etc.

It should be noted that the description above only pertains to anexample configuration of computer 130. Alternative configurations may beimplemented with additional or other sensors, storage devices,interfaces or the like. For example, the communication interface 138 maysupport other radio access technologies than the mentioned UMTS and LTE.

When the computer 130 functions as a base station, the communicationinterface 138 can further have a respective air interface (providinge.g. E-UTRA protocols OFDMA (downlink) and SC-FDMA (uplink)) and networkinterfaces (implementing for example protocols such as S1-AP, GTP-U,S1-MME, X2-AP, or the like). Moreover, the computer 130 may have one ormore antennas and/or an antenna array. The present disclosure is notlimited to any particularities of such protocols.

The methods as described herein are also implemented in some embodimentsas a computer program causing a computer and/or a processor and/or acircuitry to perform the method, when being carried out on the computerand/or processor and/or circuitry. In some embodiments, also anon-transitory computer-readable recording medium is provided thatstores therein a computer program product, which, when executed by aprocessor/circuitry, such as the processor/circuitry described above,causes the methods described herein to be performed.

It should be recognized that the embodiments describe methods with anexemplary ordering of method steps. The specific ordering of methodsteps is, however, given for illustrative purposes only and should notbe construed as binding.

It should also be noted that the division of the control or circuitry ofFIG. 12 into units 131 to 140 is only made for illustration purposes andthat the present disclosure is not limited to any specific division offunctions in specific units. For instance, at least parts of thecircuitry could be implemented by a respective programmed processor,field programmable gate array (FPGA), dedicated circuits, and the like.

All units and entities described in this specification and claimed inthe appended claims can, if not stated otherwise, be implemented asintegrated circuit logic, for example on a chip, and functionalityprovided by such units and entities can, if not stated otherwise, beimplemented by software.

In so far as the embodiments of the disclosure described above areimplemented, at least in part, using software-controlled data processingapparatus, it will be appreciated that a computer program providing suchsoftware control and a transmission, storage or other medium by whichsuch a computer program is provided are envisaged as aspects of thepresent disclosure.

The methods as described herein are also implemented in some embodimentsas a computer program causing a computer and/or a processor and/or acircuitry to perform the method, when being carried out on the computerand/or processor and/or circuitry. In some embodiments, also anon-transitory computer-readable recording medium is provided thatstores therein a computer program product, which, when executed by aprocessor/circuitry, such as the processor/circuitry described above,causes the methods described herein to be performed.

It should be recognized that the embodiments describe methods with anexemplary ordering of method steps. The specific ordering of methodsteps is, however, given for illustrative purposes only and should notbe construed as binding.

It should also be noted that the division of the control or circuitry ofFIG. 8 into units 131 to 140 is only made for illustration purposes andthat the present disclosure is not limited to any specific division offunctions in specific units. For instance, at least parts of thecircuitry could be implemented by a respective programmed processor,field programmable gate array (FPGA), dedicated circuits, and the like.

All units and entities described in this specification and claimed inthe appended claims can, if not stated otherwise, be implemented asintegrated circuit logic, for example on a chip, and functionalityprovided by such units and entities can, if not stated otherwise, beimplemented by software.

In so far as the embodiments of the disclosure described above areimplemented, at least in part, using software-controlled data processingapparatus, it will be appreciated that a computer program providing suchsoftware control and a transmission, storage or other medium by whichsuch a computer program is provided are envisaged as aspects of thepresent disclosure.

Note that the present technology can also be configured as describedbelow.

(1) An apparatus comprising circuitry configured to perform a transportchannel processing chain (TrCH proc), the transport channel processingchain (TrCH proc) comprising sub-carrier puncturing function (708;1108), the sub-carrier puncturing function comprising puncturing, ineach subframe (TTI) of a composite transmission time interval (CTTI), aset of subcarriers from at least one mapped physical resource block(PRB).

(2) The apparatus of (1), wherein the circuitry is configured topuncture the set of subcarriers so that the sets of subcarriers that arepunctured are different between subframes (TTI) of a compositetransmission time interval (CTTI).

(3) The apparatus of anyone of (1) or (2), wherein the transport channelprocessing chain is based on a composite transmission time interval(CTTI) that comprises two or more subframes (TTI).

(4) The apparatus of anyone of (1) to (3), wherein the transport channelprocessing comprises mapping (707, 1107), in each subframe (TTI) of acomposite transmission time interval (CTTI), a transport block (TrBlk_n)to an integer number of physical resource blocks (PRBs) in a singlesubframe (TTI).

(5) The apparatus of anyone of (1) to (4), wherein the transport channelprocessing (TrCH proc) comprises rearranging (709; 1109), thesubcarriers that remain after puncturing, in the frequency domain tooccupy the allocated frequency resources.

(6) The apparatus of anyone of (1) to (5), wherein the circuitry isconfigured to transmit a 3 subcarrier sub-PRB transmission or a 6subcarrier sub-PRB transmission.

(7) The apparatus of anyone of (1) to (6), wherein the compositetransmission time interval (CTTI) comprises a fixed predefined number ofsubframes and the base number of physical resource blocks (PRBs) ischanged depending on the number of sub-carriers to be used in a sub-PRBtransmission.

(8) The apparatus of anyone of (1) to (7), wherein the base number ofphysical resource blocks (PRBs) is fixed to a predefined number and thecomposite transmission time interval (CTTI) is adapted to the number ofsub-carriers used in the sub-PRB transmission.

(9) The apparatus of anyone of (1) to (8), wherein the circuitry isconfigured to receive DCI (downlink control channel information)signaling indicating parameters of the sub-PRB allocation.

(10) The apparatus of anyone of (1) to (9), wherein the transportchannel processing chain comprises repeating (1112) resource elements inother subcarriers of a sub-PRB waveform in the same subframe

(11) The apparatus of anyone of (1) to (10), wherein the circuitry isconfigured to map (1107; 1108) a transport block (TrBlk_n) to a singlesubcarrier per sub frame, and wherein the transport channel processingchain comprises repeating (1112) the resource elements of each subframeof the single carrier in other subcarriers in the same OFDM symbol ofeach sub frame.

(12) The apparatus of anyone of (1) to (11), wherein the circuitry isconfigured to transmit the individual subcarriers with different powers.

(13) The apparatus of anyone of (1) to (12), wherein the transportchannel processing chain comprises multiplexing (1111) of referencesignals into a single subcarrier.

(14) The apparatus of anyone of (1) to (13), wherein the circuitry isconfigured to receive downlink control messaging signaling indicatingthat the circuitry shall perform low Peak-to-Average Power Ratio (PAPR)uplink transmission.

(15) The apparatus of anyone of (1) to (14), wherein the transportchannel processing chain (TrCH proc) is a Physical Uplink Shared Channelresources (PUSCH) transport channel processing chain.

(16) An apparatus comprising circuitry configured to receive sets of apredefined number of subcarriers in each subframe and consider theremaining subcarriers as being punctured.

(17) The apparatus of (16), wherein the circuitry is configured toreceive an indication of a UE's uplink transmission preferences to thenetwork via higher layer signaling.

(18) The apparatus of anyone of (16) or (17), wherein the circuitry isconfigured to transmit an indication of the use of Peak-to-Average PowerRatio (PAPR) uplink transmission to the user equipment via higher layersignaling.

(19) The apparatus of anyone of (16) or (17), wherein the apparatus is abase station that receives higher layer signaling from a UE.

(20) The apparatus of anyone of (16) to (19), wherein the apparatus is abase station that transmits higher layer signaling to a user equipment.

(21) A method for performing a transport channel processing chain, thetransport channel processing chain comprising sub-carrier puncturing(708; 1108), the sub-carrier puncturing function comprising puncturing,in each OFDM symbol of each subframe (TTI) of a composite transmissiontime interval (CTTI), a set of subcarriers from at least one mappedphysical resource block (PRB).

(22) The method of (21), wherein the transport channel processing chainfurther comprises rearranging (709; 1109), the subcarriers that remainafter puncturing, in the frequency domain to occupy the allocatedfrequency resources.

(23) The method of (21), wherein the transport channel processing chainfurther comprises repeating (1112) resource elements in othersubcarriers of a sub-PRB waveform in the same OFDM symbol of eachsubframe (TTI).

(24) A computer program comprising program code causing a computer toperform the method according to anyone of (21) to (23), when beingcarried out on a computer.

(25) A non-transitory computer-readable recording medium that storestherein a computer program product, which, when executed by a processor,causes the method according to anyone of (21) to (23) to be performed.

Abbrevations

3GPP 3rd Generation Partnership Project

LTE Long Term Evolution

VoLTE Voice over LTE

IoT Internet of Things

MTC Machine-type Communication

mMTC massive MTC

NB-IoT NarrowBand IoT (Release-13)

eNB-IoT enhanced NB-IoT (Release-14)

eMTC enhanced MTC (Release-13)

feMTC further enhanced MTC (Release-14)

efeMTC even further enhanced MTC (Release-15)

UE User Equipment

UL Uplink

PUSCH Physical Uplink Shared Channel

PRB Physical Resource Block

CP Cyclic Prefix

DMRS Demodulation Reference Signal

FDMA Frequency-Division Multiple Access

SC-FDMA Single-Carrier FDMA

OFDM Orthogonal Frequency-Division Multiplexing

DFT Discrete Fourier Transform

DFT-s-OFDM DFT-spread-OFDM

QPSK Quadrature Phase-Shift Keying

QAM Quadrature Amplitude Modulation

TTI Transmission Time Interval

RV Redundancy Version

RE Resource Element

LLR Log-Likelihood Ratio

TrBlk Transport Block

PSD Power Spectral Densitiy

PAPR Peak-to-Average Power Ratio

CTTI Composite Transmission Time Interval

DCI Downlink Control Channel Information

TBS Transport Block Size

MCS Modulation and Coding Scheme

RRC Radio Resource Control

References

[1] RP-170732, “New WID on Even further enhanced MTC for LTE,” Ericsson,Qualcomm

[2] TS 36.211 v14.2.0, Physical channels and modulation

[3] TS 36.212 v14.2.0, Evolved Universal Terrestrial Radio Access(E-UTRA); Multiplexing and channel coding

[4] TS 36.213 v14.2.0, Evolved Universal Terrestrial Radio Access(E-UTRA); Physical layer procedures

1. An apparatus comprising circuitry configured to perform a transportchannel processing chain, the transport channel processing chaincomprising sub-carrier puncturing function, the sub-carrier puncturingfunction comprising puncturing, in each subframe of a compositetransmission time interval, a set of subcarriers from at least onemapped physical resource block.
 2. The apparatus of claim 1, wherein thecircuitry is configured to puncture the set of subcarriers so that thesets of subcarriers that are punctured are different between subframesof a composite transmission time interval.
 3. The apparatus of claim 1,wherein the transport channel processing chain is based on a compositetransmission time interval that comprises two or more subframes.
 4. Theapparatus of claim 1, wherein the transport channel processing comprisesmapping, in each subframe of a composite transmission time interval, atransport block to an integer number of physical resource blocks in asingle subframe.
 5. The apparatus of claim 1, wherein the transportchannel processing comprises rearranging, the subcarriers that remainafter puncturing, in the frequency domain to occupy the allocatedfrequency resources.
 6. The apparatus of claim 1, wherein the circuitryis configured to transmit a 3 subcarrier sub-PRB transmission or a 6subcarrier sub-PRB transmission.
 7. The apparatus of claim 1, whereinthe composite transmission time interval comprises a fixed predefinednumber of subframes and the base number of physical resource blocks ischanged depending on the number of sub-carriers to be used in a sub-PRBtransmission.
 8. The apparatus of claim 1, wherein the base number ofphysical resource blocks is fixed to a predefined number and thecomposite transmission time interval is adapted to the number ofsub-carriers used in the sub-PRB transmission.
 9. The apparatus of claim1, wherein the circuitry is configured to receive downlink controlchannel information signaling indicating parameters of the sub-PRBallocation.
 10. The apparatus of claim 1, wherein the transport channelprocessing chain comprises repeating resource elements in othersubcarriers of a sub-PRB waveform in the same subframe.
 11. Theapparatus of claim 1, wherein the circuitry is configured to map atransport block to a single subcarrier per subframe, and wherein thetransport channel processing chain comprises repeating the resourceelements of each subframe of the single carrier in other subcarriers inthe same OFDM symbol of each sub frame.
 12. The apparatus of claim 1,wherein the circuitry is configured to transmit the individualsubcarriers with different powers.
 13. The apparatus of claim 1, whereinthe transport channel processing chain comprises multiplexing ofreference signals into a single subcarrier.
 14. The apparatus of claim1, wherein the circuitry is configured to receive downlink controlmessaging signaling indicating that the circuitry shall perform lowPeak-to-Average Power Ratio uplink transmission.
 15. The apparatus ofclaim 1, wherein the transport channel processing chain is a PhysicalUplink Shared Channel resources transport channel processing chain. 16.An apparatus comprising circuitry configured to receive sets of apredefined number of subcarriers in each sub frame and consider theremaining subcarriers as being punctured.
 17. The apparatus of claim 16,wherein the circuitry is configured to receive an indication of a UE'suplink transmission preferences to the network via higher layersignaling.
 18. A method for performing a transport channel processingchain, the transport channel processing chain comprising sub-carrierpuncturing, the sub-carrier puncturing function comprising puncturing,in each OFDM symbol of each subframe of a composite transmission timeinterval, a set of subcarriers from at least one mapped physicalresource block.
 19. The method of claim 18, wherein the transportchannel processing chain further comprises rearranging, the subcarriersthat remain after puncturing, in the frequency domain to occupy theallocated frequency resources.
 20. The method of claim 18, wherein thetransport channel processing chain further comprises repeating resourceelements in other subcarriers of a sub-PRB waveform in the same OFDMsymbol of each sub frame.